If a Bank That Faces a 10% Reserve Ratio Received

If a bank that faces a 10% reserve ratio received a deposit of $50,000 and makes a loan to a customer for $5,000,what is the consequence if the bank then deposits the rest of the funds at the Federal Reserve?

A) Excess reserves increase by $50,000.
B) Excess reserves increase by $45,000 and required reserves increase by $5,000.
C) Excess reserves increase by $5,000 and required reserves increase by $45,000.
D) Excess reserves increase by $40,000 and required reserves increase by $5,000.
E) Reserves are not affected.